1. Field of the Invention
The present invention relates to a vehicle hood structure that includes a hood inner panel and a hood outer panel and that has good pedestrian protection performance when a vehicle collides with a pedestrian and good front collision performance when the vehicle collides with another vehicle.
2. Description of the Related Art
There are many design requirements to be satisfied other than pedestrian protection performance for a vehicle hood structure including a hood inner panel and a hood outer panel. In particular, when a front collision with another vehicle occurs, it is required that the vehicle hood structure be deformed such that the center of the vehicle hood structure rises and is bent into an angular shape in sectional view so as to prevent entrance into the vehicle. In order to facilitate this bending deformation, a structure that includes a crush bead extending in the vehicle width direction has been proposed (see, for example, Japanese Unexamined Patent Application Publication No. 2005-75163, Japanese Patent No. 4407755, and Japanese Unexamined Patent Application Publication No. 2005-239092). Furthermore, according to these patent documents, the crush bead is applied to the hood inner panel provided with hat-shaped beads extending in the vehicle front-rear direction.
Furthermore, in order to obtain both the front collision performance and the pedestrian protection performance, some vehicle hood structures (see FIGS. 7A to 7C) have been proposed which include a hood outer panel 10 and a hood inner panel 20 that includes a crush bead 20d and a plurality of substantially hat-shaped beads 20f extending in the vehicle width direction as illustrated in FIG. 8 (for example, see Japanese Unexamined Patent Application Publication No. 2006-44311).